Form stripping scaffold



May 22, 1962 3,035,659

R. A. SIMS FORM STRIPPING SCAFFOLD 2 Sheets-Sheet 1 Filed March 16, 1961 q, 'd' P05546 5//1//5 INV ENTOR T Q u.

ATTORNEY 5 May 22, 1962 R. A. slMs FORM STRIPPING scAFFoLD 2 Sheets-Sheet 2 Filed March 16, 1961 INVENTOR P0554? S//ws BY W )L M10 ATTORNEYS United States PatentOiiice 3,035,659 Patented May 22, 1962 3,035,659 FORM STRIPPING SCAFFOLD Robbie A. Sims, P.0. Box GG, Farmerville, La. Filed Mar. 16, 1961, Ser. No. 96,242 11 Claims. (Cl. 182--13) This invention relates to scalolds and has particular reference to a new and improved scaffold for stripping forms from the underside of concrete bridges or the like.

In the construction of concrete bridges there are generally provided concrete forms on the underside thereof which must necessarily be stripped after the poured concrete has been allowed to set. Such bridge structures also generally have supporting piers intermedia-te the ends of the bridge. As is apparent, the provision of a conventional line-hung scaffold extending across the underside of the bridge and secured thereto for stripping the concrete forms is necessarily a tedious and otherwise diicult operation. This is due to the fact that the Scaffolding must be stripped across the entire length of the ings of the prior yart scaffolding and provides a reliable and safe structure for stripping the forms from the underside of a concrete bridge, provision being made for moving the scaffolding along the -length of the bridge by personnel working on the scaolding, together with means for moving the apparatus past otherwise obstructing piers which support the bridge.

An object of this invention is =to provide a form stripping scaffold having a separable platform structure which provides for moving the scalold past otherwise obstructing bridge piers.

Another object of this invention is to provide a wheeled form stripping scaffold which is operable by personnel standing on the platform to move the apparatus along the length ofthe bridge, as desired.

Still a further object of this invention is to provide a form stripping scaffold of a wheel and axle mounted type,

'together with opposed pivotable platform frame means Vwhich allow their pivotal movement downwardly away from one `another to avoid a pier obstruction, and being further provided a winch and cable means operable from the top of the bridge to return and maintain the platform frame means to their normally horizontal position after an obstruction has been passed.

Still a further object of this invention is to provide a form stripping scaffold which includes chain fall driving means operably connected to an `axle carrying the wheels, the chain fall being operable from the platform underneath the bridge to move the apparatus along the length of the pier.

Still further objects, advantages, and novel features of this invention will become apparent in the specilication, claims, and accompanying drawing wherein:

FIGURE l is a ront elevation view of the apparatus according to this invention mounted on a concrete bridge;

FIGURE 2 is a partial perspective view of the apparatus shown in FIGURE l; and V FIGURE 3 is an elevation View generally similar to FIGURE 1 but showing the structure positioned for move- ,ment past an obstructing bridge pier.

Reference is now made to the accompanying drawings wherein like numerals refer to similar elements in vari- .ous views.

There is shown in FIGURE 1 a lnewly formed concrete bridge 10 having conventional supporting beams 12 extending longitudinally thereof. As is known in the art, in the construction of such a bridge the beams 12 are generally reinforced with concrete and, consequently, the underside of the bridge 10 has suitable forms (not shown) extending therealong to properly contain the concrete during setting thereof, as is apparent. After the concrete has been allowed to set, the forms are then stripped from the underside ofthe bridge. To this end, there is provided a scaold indicated generally at 14 from which personnel may strip these forms.

The scaffold 14 includes `an upper frame 16 which is of generally oblong construction and extends at its ends beyond the sides of bridge 10. The upper `frame 16 includes transverse beams 18 cooperatively secured to longitudinal beams 20, as by welding or the like. This upper frame 16 is of a suiciently rigid construction to support considerable weight, as will be apparent; and, therefore, numerous alternative structural arrangements will be apparent to those skilled in the art.

Secured to the underside ofthe upper frame 16 are two longitudinally extending wheel mounting structures 22, 22 ydisposed in parallel and spaced apart relationship one to the other. As best shown in FIGURE 2, lthe structures 22, 22 include spaced apart beams 24, and 26, connected at their front 4and rear ends respectively, by tie plates 28 and 30. In this regard, the rear tie plate of lthe lett-hand wheel mounting structure is omitted for convenience of illustration.

Mounted within the respective mounting structures 22, 22 are front wheels 30 and rear wheels 32 (the left rear wheel being omitted for clarity). The front wheels and the rear wheels are shown mounted on axles 34, 34 respectively which are suitably journaled into the mounting structures 22, 22 by conventional means (not shown).

The scaffold 14 is thereby supported on the wheel assembly to provide for movement along the length of the bridge 10, as will become apparent.

Secured to the ends of the upper frame 16 by pivot connections 36, 36' are lower frame members 38, 38 mounted in opposed relationship.

The ylower frame members 38, 38' are shown to comprise vertical channels 40, 40 joined together by framing struts 42, 42'. In this regard, the upper ends of the channels 40, 40' are pivotally connected to the endmost longitudinal upper frame beams 20 and the ends of the outer transverse frame beams 18 by pivot pins or the like at 36, 36 as is apparent. A ladder 43 is conveniently secured adjacent the inward vertical channels 40 (FIG- URE 2).

Secured to the lower ends of the channels 40, 40' are horizontal platforms 44, 44', made of wood, metal plate or the like, these platforms 44, 44 being mounted to platform channels 46, 46', which are secured as by welding to the channels 40, 40. Additional structural support for the platforms 44, 44 is provided by struts 48, 48 which are fixed to the channels 40, 40 at one end and are secured at their lower ends to the platforms 44, 44 in angular relationship thereto. As is understood, the lower frame members 38, 38' provide unitary, rigid structures, by virtue of the above-described ixed connections between elements 40, 44, 48 and also 40', 44', 48 respectively. By virtue of the pivotal connections 36, 36 between the lower frame members 38, 38 and the ends of the upper frame 16, the lower `frame members 38, 3S' have a tendency to pivot downwardly and away from one another by virtue of the moments of force about the pivot connections 36, 36. In order to counteract this force and otherwise provide a means for holding the platforms 44, 44 in horizontally yaligned relationship, there is provided a cable supporting arrangement designated generally at 50. To this end, there is mounted on the upper frame 16 a cable winch 52. This winch 52 if of conventional construction preferably having a brake and clutch arrangement (not shown) and may be either hand operated by a handle 54, or powered, as by an electric drive motor (not shown). operatively wound on the winch is Va Vcable 56 which passes about a first sheave 58 which is rotatably mounted on the end of the upper frame 16. A second sheave 60 yis mounted on the lower frame member 38 intermediate adjacent vertical channels 46', as best shown in FIGURES 1 and 3.

Extending upwardly from the inner ends of the platforms-44, 44V are spaced apart bracket plates 62, 62 and 62,' l62', respectively, and xed to these brackets are guide rods 64, 64', as by welding.

' The cable 56 passes under the guide rod 64 and is then passed about a pulley block 66 having a hook 68 extending therefrom. The cable is then passed back under the rod 64 and joined vat its end to a channel 40', by any Ysuitable connection',

A second cable '72 is secured to a left-hand channel 40 and passes under the left-hand guide rod 64. This cable 72 has a connecting ring 74 secured to its free end, adapted for engagement with the hook 68 on the pulley block 66.

Referring again to the upper h-ame 16 and the associated wheel and axle structure, there is shown in FIG- YURES l and 3 a drive means 76 for moving the scaffold 14 along the bridge.

From the front axle 34, to which the right front wheel 30.is secured, there extends to a reduction gear unit 78, which is secured to the outside of the mounting structure 22 by any suitable means such as fa tie plate (not shown) welded thereto. Operatively extending from the reduction gear unitV 78 isa stubrshaft 80, which has a gear 82 fixed thereto. A spacer shaft 84 is secured to the under side of the frame 16 as by downwardly depending bearing plates 36.` A gear 88 is secured to the inner end of the shaft 84 for engagement with the gear 82 on the shaft 80. A sprocket wheel 93 is xed to the outer end of the spacer shaft 84, the'position of the sprocket wheel 90 being such that it extends beyond the side of the bridge A10. An endless drive chain 92 is trained over the sprocket wheel 90, the drive chain 92 being of suihcient length so as to be operable from personnel when on Vthe'platform 44'.

Consideration will now be given to the operation of the scaffold 14 during the form stripping operation.

The scaffold 14 is moved to the end of a bridge that is to be stripped of forms along its underside. In this regard, the lower frame members are 38, 38 are positioned to ride on the upper side of the upper frame by virtue of Ythe pivot connection 36, 36 during transportation, and

the scaffold 14 may be towed by a truck or the like. When the scalfold 14 reaches an end of the bridge, the

Y lower frame members 38, 38 are manually pivoted down- Y the top `of the bridge; or, in instances where the level of the ground below the bridge is not unduly great, by

workmen from the ground.

YAfter the connection is made, the cable 56 is taken up by the winch 52, and the lower frame members 38, 38

are raised to the positions shown in FIGURES l and 2.

VWorkmen may then descend the ladder 43 and commence the form stripping `operation along the underside of the bridge 10, as is apparent.

e The scaffold is moved along the bridge, as desired, by

' driving the wheel 30through drive chain 92, sprocket 90,

gears 88 and 82, reduction (gear unit 78 and the axle 34. It will 'thus be appreciated that the scaold need not be attended yfrom the surface of the bridge 10, as the scaffold is moved along its length.

. When obstructing piers are encountered, the workmen leave the platforms 44, 44' by the ladder 43 and the Winch 52 is actuated to unwind the cable 56, allowing the supporting members 38, 38' to assume the general position in FIGURE 3, except the hook 6.8 is still connected to the connecting ring 74. Additional cable 56 is then unwound from the winch 52, relieving the tension on the cables 56 and 72 so that the hook 68 may be separated from the ring 74, as by a grappling hook, or manually from the ground, as desired.

VThe scaffold is then moved along the bridgepast the pier, and the scaffold 14 is again assembled yas described above, the form stripping operation continuing again as the workmen move the scaifold 14 along bridge 10.

After the operation is completed, the platforms 44, 44 are disconnected in the manner previously described, and the lower frame members 38, 38 are pivoted from their positions in FIGURE 3 upwardly about connections 36, 36 so they rest on the upper surface of the upper frame 16, and the scaiold may then be towed to another bridge site as desired. This arrangement is shown in phantom lines in FIGURE 3 wherein the platform members 44, 44 extend upwardly from the upper frame 16.

As will be apparent to those skilled in the art, numerous modifications may be made to the mechanical features of this invention without departing from the scope thereof. For instance, the driving means 76 may be modified to provide a positive chain drive on both sides of the frame 16, and the chain drive may act on both the front 'and rear axles. The significant feature that is preferably utilized is a drive means operable from per- Ysonnel on the platforms 44, 44.

Vmay be made between the platforms 44, 44 to obviate danger toV personnel, should there be ya failure in the cable drive means 50. Safety guide rails may be placed Valong the platform 44, 44 to provide protection for the Workmen as is apparent.

Also, another similar cable arrangement may be provided for the opposite sides of 4the platforms 44, 44', driven from a common'shaft `joining the winch 52 with another Winch, as is apparent. Such structural modiiications will depend to some extent on the size of the particular scaffold structure. Further mechanical refinements within the scope of this invention include a telescoping structure, e.g. the upper frame 16 and the platforms 44, 44' may telescope into each other to decrease the width of the scaffold 14 during travel over a conventional road.

It will thus be seen that the object of this invention, together with many practical advantages, are successfully achieved.

As various possible further embodiments may be made of the mechanical features of this invention, all without departing from the scope thereof, it is to be understood that all matters herein set fonth or shown in the accom panying drawing are to be interpreted in 'an illustrative, and not aV limiting sense.

What is claimed is:

1. Scaffold apparatus for stripping forms from the underside of pier-supported concrete bridges and the like comprising: upper frame means; spaced apart wheels mounted on said upper frame means to providevmovement thereof along Vthe bridge; lower frame means including platform means pivotally connected to said upper frame means, said lower frame means being pivotable between a first position wherein said platform means is disposed in a generally horizontal plane beneath the bridge and -a second position wherein said platformV means is disposedy transversely laway from the bridge Vsupporting piers, whereby said upper frame means is movable past the bridge supporting piers, and a third position wherein 5 said lower frame means is carried on said upper frame means above the bottom of the wheeis and said platform means extends upwardly therefrom, whereby the apparatus is movable on roads and the like to and from positions of use.

2. Apparatus according to claim 1 including drive means mounted on said upper frame means and operatively connected to said lower frame means to provide movement of said lower frame means between said positions.

3. Apparatus according to claim 2 wherein said drive means includes winch means mounted on said upper frame means; Vcable means carried by said winch means and operatively mounted on said lower frame means; a detachable connection for said cable means, whereby said winch means is operable to pivot said lower frame means, from said second position to said rst position.

4. Apparatus according to claim l including wheel drive means operable from said platform means.

5. Apparatus according to claim 4 wherein said wheel drive means includes reduction gear means operatively connected to -at least one of said Wheels; and chain fall drive means operatively connected to said reduction gear means.

6. Apparatus according to claim 1 wherein said lower frame means includes two lower frame members pivotally connected to said upper frame means at the opposite end regions thereof, each of said members including an inwardly extending platform member secured to the lower ends thereof, said platform members extending upwardly when in said third position.

7. Apparatus according to claim 6 including winch means mounted on said upper frame means; cable means joined to said winch means and carried by one of said platform members; and means detachably joining said cable means to said other platform member.

8. Apparatus `according to claim 7 wherein said last mentioned means includes second iixed cable means carried by said other platform; and means detachably connecting said two cable means.

9. Apparatus according to claim 7 including reduction gear means operatively connected to at least one of said wheels; and chain -full drive means operably connected to said reduction gear means and operable from at least one of said platform members.

10. scaffold lapparatus for stripping forms from the underside of pier supported concrete bridges and the like comprising: upper frame means; spaced apart wheels mounted on said upper frame means to provide movement thereof along the bridge; rst and second lower frame members pivoted to -the opposite end regions of said upper frame means, each of said lower frame members including cooperating platform members secured to the lower ends thereof in opposed relationship; winch means mounted on said upper frame member; cable means joined to said winch means and extending to at least one of said plattform members; means detachably connecting said cable means to said platform members so that actuation of said winch means and cable means pivots said platform members upwardly to opposed horizontal positions beneath Ithe bridge; and wheel drive means operatively connected to at least one of said wheels for movement of said upper frame member from a position adjacent `at least one of s-aid platform mem-bers when in said horizontal positions.

11. Apparatus defined in claim 10 wherein said opposed horizontal platform member positions defmes a first position, said platform members being pivotable downwardiy away from one another to define a second position transversely free of the piers, and pivotable to a third position wherein said platform members -are carried in upwardly extending relationship on said upper frame means above the bottom of said wheels whereby the apparatus is movable on roads and the like to and from positions of use.

References Cited in the le of this patent UNITED STATES PATENTS 580,415 Miller Apr. 13, 1897 1,715,367 Jagschitz June 4, 1929. 2,067,344 Ringe Jan. 12, 1937 2,520,403 Hirsh Aug. 29, 1950 2,639,950 Wheeler May 26, 1953 2,669,490 Kaufman Feb. 16, 1954 2,915,137 Troche Dec. 1, 1959 2,919,763 Kronkhaus Jan. 5, 1960 FOREIGN PATENTS 174,704 Great Britain I an. 27, 1922 

